First of all try lspci and see whether your sound card was detected.
If it was, then lsmod to see whether any driver was loaded for your driver.
If was not, then check up on the internet and find out the driver's name for your sound card. I have forgotten where in RH you can find the modules, but maybe someone else can help you.
If you have that specific module, then /usr/sbin/modprobe module-name (must be logged as root).
Try again lsmod .If the module is listed, then worked. Otherwise...